Video streaming and mesh-based peer-to-peer ﬁle sharing are two of the most bandwidth-demanding applications in the current Internet. In particular non-popular video streaming is on the increase, and future networks are likely to be even more involved in this type of application. Another expected ma jor deﬁning trait of future network is heterogeneity, not only with respect to access technologies, but also several other factors, such as user mobility and terminal capability. This extended abstract delineates some of the most pressing challenges to be faced by mesh-based collaborative video streaming systems, with particular focus on maintaining adequate Quality of Experience (QoE).